Effect of coexisting hypertension, blood pressure control, and antihypertensive treatment on QT interval parameters in type 2 diabetics: A cross-sectional study

Abstract

Objectives: To study the electrocardiogram (ECG) based QT parameters namely QTc (heart rate corrected QT), QTd (QT dispersion) in treated type 2 diabetics (T2D) and the effect of hypertension (HTN), blood pressure (BP) control, and antihypertensives used on the above parameters. Materials and Methods: We performed a cross-sectional study in a tertiary care hospital of Gujarat, India, on 199 T2D (67 males and 132 females). Standard 12-lead ECG was recorded to derive QTc (Bazett's formula), QTd, and ECG left ventricular hypertrophy (LVH). QTc >0.43 s in male and >0.45 s in female and QTd >80 msec were considered abnormal. Results: Hypertensives (n = 138) and normotensives (n = 61) were comparable for most confounders. Hypertensives had better profile of QTc and QTd than normotensives. T2D with controlled BP revealed slightly better, though insignificant; QTc, QTd than those with BP uncontrolled. QT parameters were not significantly correlated with age, heart rate, or BP. Qualitative differences exceeded quantitative difference in QTc and QTd evaluation. There was no significant effect of use or nonuse of preventive pharmacotherapy on QT parameters. Conclusion: Low-to-moderate prevailing cardiac repolarization abnormality in T2D with very low ECG LVH was unaffected by HTN as a disease, its control status, and treatment modalities suggesting primary preventive role of antihypertensive use without class difference.